Consolidated Balance Sheets (Parenthetical) (USD $)	Sep. 30, 2011	Dec. 31, 2010
Treasury stock, shares	261,294	133,564
Series A Preference Shares [Member]
Preference Shares, par value	$ 0.01	$ 0.01
Preference Shares, shares authorized	350,000	350,000
Preference Shares, issued	78,260	0
Series B Preference Shares [Member]
Preference Shares, par value	$ 0.01	$ 0.01
Preference Shares, shares authorized	100,000	100,000
Preference Shares, issued	30,000	0
Ordinary Shares Class A [Member]
Ordinary Shares, par value	$ 0.01	$ 0.01
Ordinary Shares, shares authorized	75,000,000	75,000,000
Ordinary Shares, shares issued	18,681,467	16,571,865
Ordinary Shares, shares outstanding	17,654,969	16,438,301
Ordinary Shares Class B [Member]
Ordinary Shares, par value	$ 0.01	$ 0.01
Ordinary Shares, shares authorized	30,000,000	30,000,000
Ordinary Shares, shares issued	13,200,305	14,740,461
Ordinary Shares, shares outstanding	13,200,305	14,740,461